Hitherto, there have been several proposals by applicant for the production of packaging of the general type concerned here. Examples are seen in applicant's prior U.S. Pat. Nos. 4,685,274 and 4,840,271, and applicant's pending application Ser. Nos. 07/488,664 and 07/499,644, all of which disclosures are incorporated herein by reference.
The present invention relates to an improvement or modification in the invention shown in at least one or more of applicant's U.S. Pat. No. 4,840,271, and applicant's pending application Ser. Nos. 07/488,664 and 07/499,644. It has been found necessary to provide for desired packaging of red meats to have a flexible web of gas permeable plastics material stretchingly engage across the meat. This arrangement places tension forces in the flexible web and makes the product more consumer acceptable.
The specification of U.S. Pat. No. 4,840,271 describes a packaging of the type shown by FIGS. 1 and 2 herein.
The specification of applicant's pending application Ser. No. 07/499,644 describes a packaging of the type shown by FIG. 3 herein.
In FIGS. 1 and 2 there is shown packaging of clear plastics material comprising a relatively rigid base 1 with an upper lid 9. Goods 3 are packaged within the base 1 and a skin wrapping material 7 skin wraps the goods 3 relative to the base 1. The skin wrapping material 7 and the lid 9 are bonded around a peripheral lip 5 as by heat bonding which seals the packaging. The lid 9 is relatively rigid and of similar thickness to that of the base 1. Both the base 1 and the lid 9 are substantially gas impervious in certain embodiments and the skin wrapping material 7 is a relatively thin web which is gas permeable. A free space 11 is provided between the skin wrapping material 7 and the lid 9 and a gas is provided within the free space 11 for enhancing preservation of the packaged goods 3. The gas can be provided to enhance the colour keeping properties as well as the non-bacteria growth properties. The flexible web 7 is gas permeable such that the gas within the free space 11 can permeate the web 7 to contact the goods 3 to enhance the keeping properties of the goods 3. It has been found that after an extended period of time, as for example several weeks, as the gas in free space 11 permeates the web 7 there is at least partial pressure equalization so that the web 7 is no longer tightly skin wrapping the goods 3. The appearance of the package can then be unpleasant and thus the package can be rejected by an intending purchaser.
In the embodiment shown in FIG. 3 the construction is very similar to that shown in FIGS. 1 and 2, but here the skin web 7 is stretched downwardly onto lower lips 13. The height of the goods 3 is above the height of the lower lips 13 and hence by bonding of the skin web 7 at region 17 to the lower lips 13, it is possible to maintain the tension displacement of the web 17 and to thus hold the goods 3 firmly to the base 1. In the embodiments shown in the above described specification of Ser. No. 07/499,644 it can be seen that the goods, particularly red meats, are in firm contact with the base of the outer container. It has been found necessary in some instances to configure the base from an opaque rigid material so that the undersurface of the meat cannot be viewed. This is because when the meat is in close contact with the base gases are unable to freely circulate to the surface of the meat which contacts the base and therefore that surface discolours dark brown. This is completely unattractive to an intending purchaser. By providing the base with an opaque material, any discolouration of the meat is not observed by an intending purchaser. However, because the base is opaque, many intending purchasers reject the package simply because they cannot view the entire surface of the meat.
We have discovered that by employing a different method for the production of the packages than hitherto proposed, adequate holding of the goods by the gas permeable flexible web(s) can be achieved. Certain embodiments enable the goods to be suspended between the base and the lid of the packaging and thus it is possible to enable the preserving gas to contact all surfaces of the goods by permeating through the gas permeable webs which are employed. This, in turn, enables both the lid and base, in certain embodiments to be made of clear transparent plastics material so that all surfaces of the goods can be observed by an intending purchaser.